PR #34934 switched the `getting-started` docs example from using the
index of a product in the `products` array to using the product's ID
property for indentifiying each product in the `ProductDetailsComponent`
component. However, some necessary changes in the example code and the
`start-routing.md` guide were missed in #34934, resulting in broken
instructions for the readers (see #40189).
This commit is essentially a follow-up to #34934, making the remaining
changes in the example code and the guide instructions.
Fixes#40189
PR Close#40197
This commit aligns the code and style in the `getting-started-v0` docs
example with that of the `getting-started` example more closely (except
for the the parts that are intentionally different between the two).
PR Close#40197
https://developer.mozilla.org/en-US/docs/Web/CSS/font-family
"You should always include at least one generic family name in a font-family list,
since there's no guarantee that any given font is available. This lets the browser
select an acceptable fallback font when necessary."
PR Close#40254
